Signaling system



Feb. 13,1934. 0. s. DEMAREST SIGNALING SYSTEM 3 Sheets-Sheet 1 FiledOct. 1, 1932 I .5 INVENTOR l7 C.S.D,e/ma/ ;es

ATTORNEY Feb. 13, 1934. Q s DEMAREST 1,946,615

- SIGNALING SYSTEM Filed Oct." 1, 1932 s Sheets-Sheet 2 INVENTOR C.5IDe/ma7ces ATTORNEY Feb. 13, 1934. c, s DEMAREST Q 1,946,615

SIGNALING SYSTEM Filed Oct. 1, 1932 3 Sheets-Sheet 3 [I am I! n u n w .Z32 34 5v 4 GLSZDAnmnesZ BY v ATTORNEY Patented Feb. 13, 1934 UNITEDSTATES PATENT OFFICE 1,946,615 SIGNALING SYSTEM Application October 1,1932. Serial No. 635,835

8 Claims. (Cl. 177-346) This invention relates to signaling systems andmore particularly to visual signaling systems such as used forintermittent operation or operation in sequence of lamps or otherindicating devices.

Various applications of the arrangements described herein would be toprovide intermittent or sequence flashing signals for certainindications at telephone or power switchboards, for

10 warning signals at road crossings, advertising sign displays, etc. Anobject of the invention would be to eliminate mechanically moving partsand sparking contacts for such purposes by the use of gas-filled tubes.Another object would be to provide simple means for the control of thespeed of operation of the various signals individually and in relationto each other. Another object would be to provide a signal array whereinthe individual duration and sequence of operation and release couldeasily be changed by rearrangement of the tube and rectifier elementswithout changes in the general arrangement of the display elements.

The invention may be more fully understood.

from the following description together with the accompanying drawingsin the Figures 1, 2, 3, 4 and 5 of which are shown various embodimentsof the invention. Fig. 1 shows an arrangement for interrupting a powersupply of one frequency at any other desired frequency as might berequired for operation of signals such as ringers, lamps or glow tubes.Fig. 2, in connection with Figs. 3, 4 and 5 shows arrangements toprovide consecutive operation of lamps, each remaining lightedthereafter until the end of the cycle, consecutive single operation ofsignals or consecutive intermittent operation of signals. Variouscombinations of these types of operation may be obtained by combinationsof Figs. 3, 4 and 6 with Fig. 2. Similar reference characters have beenused to denote like parts in all of the figures.

In Fig. 1 is shown a gas-filled discharge tube 1, controlling theflashing of lamps G1, G2, G3, etc. The tube 1 might, for example, befilled with a gas such as neon or argon. In the grid circuit of the tube1 would .be the battery 100 so poled as to apply a negative charge tothe grid and thus keep the tube normally in a quenched condition. In thegrid to cathode circuit of this tube are two rectifier circuitscontrolling the ionization andquenching of tube 1. When switch 2 isclosed energy is supplied by the A. C. source 3, through transformer PTto 4, resistance 5, condenser 6 and resistances '7 and 8. The A. C.voltage applied to this circuit causes condenser 6 to charge throughresistance 5 and current to flow through resistances 7 and 8 such thatthe drop across resistance 8 applied between the grid and cathode oftube 1 makes the grid more positive with respect to the cathode until avalue is reached at which the gas in the tube ionizes and an arc isestablished between the anode and cathode. Anode potential is suppliedthrough transformers T2 and PT from source 1. When the arc isestablished the circuit through the windings of transformers T1, T2, and

T3 is closed and voltage is applied through T3 to the lamps G1, G2, G3,etc. causing them to oper- :0 ate. Voltage is also applied throughtransformer T1 to the stop rectifier circuit comprising rectifier 9,resistance 10, condenser 11 and resistances 12 and 13 causing condenser11 to charge through resistance 10 and current to flow throughresistances 12 and 13 such that the drop across resistance 13 is opposedto the drop across resistance 8. When the resultant voltage between gridand cathode is more negative than the value at which ionization occursthe tube will quench at the next negative half cycle of anode potential.During the time that the arc is established the impedance between thegrid and cathode of tube 1 is reduced to a low value thus creating a lowresistance shunt across resistance 8, through the timed circuits LC andresistance 13 such that the charge on condenser 6 leaks off faster thanit is built up by the action of rectifier 4. As soon as the arc isquenched the impedance of the grid-cathode path rises to a high valueand the charge on condenser 6 begins to increase until the gridpotential is again reached at which ionization occurs, causing arepetition of the cycle just described. The charge on condenser 11 leaksoff through resistances 12 and 13 during the period when the arc isquenched. Lamps G1, G2, G3, etc. are lighted during each period ofionization of tube 1, energy being supplied from source 3 throughtransformers PT, T2 and T3, and are extinguished each time the arc isquenched. 0 The frequency of operation of such an intermittent cycle andthe length of light and dark intervals may be controlled byadjustment ofthe values of resistances 5, 7, 8, 10, 12 and 13 of condensers 6 and 11.When the arc isestab- 105 lished an increase in the value of resistance10,

for instance, or the capacity of condenser 11 will cause an increase ofthe interval during which the lamps are lighted and vice versa. Adecrease in the value of resistance 7 or an in- 110 circuits of thetubes S1, S2, Sn there would be provided the batteries 100, and 100" sopoled as to apply negative charges to the grids of the respective tubesand thus keep the tubes normalLv in a quenched condition. Upon theoperation of each tube, energy is supplied from the A. C. source 1,through transformer PT, transformer t1 associated with the anode circuitand transformer is to leads A1, A2, Au which may be connected to varioussignal devices, lamps or circuits as hereinafter described. The detailedoperation of the circuit is as follows:

When switch 2 is closed, energy is supplied from source 1 throughwinding 3 of transformer PT to the start rectifier circuit of tube S1which consists of rectifier 4, resistanceli, condenser 6 and resistances7 and 8. Voltage is also applied at the same time through winding 9' oftransformer PT to the primary windings of all transformers t1, t1, etc.,associated with the anode circuits of all the tubes S1, S2, Sn. Thevoltage applied to the rectifier circuit causes condenser 6 to chargethus causing a current to flow through resistances 7 and 8, the voltagedrop across resistance 8 being applied between the grid and cathode oftube S1 through inductance 10 and resistance 15. When this voltagereaches the value at which ionization occurs an arc is establishedbetween the anode and cathode of tube S1 closing the series circuitthrough the windings of transformers t1, t2 and ta. The voltage fromwinding 9' of transformer PT is then transmitted through transformers t1and is to leads A1 which may be connected to leads B1 of Fig. 3, C1 ofFig. 4, D1 of Fig. 5 or to various combinations of these. Voltage isalso applied through transformers t1 and t: to the start rectifiercircuit of tube 8:, where the action is the same as described above inconnection with tube S1. The time delay between the operation of tube 81and tube S: is regulated by the values of resistances 5, 7 and 8 andcondenser 6. The operation of tube S: causes voltage to be applied toleads A: in a manner similar to that in which voltage was applied toleads A1. Leads A: may, in a like manner, be connected to leads B1 ofFig. 3, C: of Fig. 4, D: of Fig. 5, or any combination of these. Theoperation of tube S: causes voltage to be applied to the start"rectifier circuit of the next succeeding tube in the series, and so onuntil tube Sn is operated, applying voltage to leads A1: and thence toleads Bx of Fig. 3, Cu of Fig. 4, DR of Fig. 5, etc. Upon the operationof tube Sn voltage is applied through transformer is" associated withthis tube to the stop rectifier circuits associated with each tube ofthe series consisting of rectifier 11, resistance 12, condenser 13 andresistances 14 and 15 for tube S1 and for the other tubes consisting ofsimilar elements with similar reference characters with the addeddesignation prime, etc. Voltage drops opposing those across resistance 8are built up across resistance 15 and in a time determined by the valuesresistance 12 and condensers 13 will reduce the grid potentials of eachtube to the point where ionization ceases, this occurring simultaneouslyin all the tubes of the series, and removing voltage from all the leadsA1. A2, As. The charges on condensers 6 of all the tubes will haveleaked off during the time that the tubes are ionized and on condensers13 after they have been quenched as described in connection with thestart and "stop rectifiers of Fig. 1. If switch 2 remains closed thevoltage from winding 3 of transformer PT will again begin to chargecondenser 6 of tube S1 and the cycle will be restarted.

Fig. 3 shows lamps, or groups of lamps, L1, L2, Ln associated with leadsB1, B2, Bu which may be connected respectively to leads A1, A2, Au asdescribed above. Each lamp or group of lamps may, for instance,correspond to a letter, number, word, etc., of a display which will thusbe spelt out letter by letter or word by word, be extinguished afterthedisplay has been completely illuminated and repeat the cycle as longas power is applied to transformer PT.

Fig. 4 shows a series of gas-filled tubes 81', S2, Sn corresponding totubes S1, S2, S1: of Fig. 2 and corresponding lamps or groups of lampsL1, L2, Lu which are arranged to operate in sequence as tubes S1, S2, Snare operated and to be extinguished in sequence after a predeterminedinterval for each. Leads C1, C2, C1: are connected respectively to leadsA1, A2, Au of Fig. 2. The detailed operation of the circuit is asfollows:

In the grid circuits of tubes S1, S1 and S3, respectively, would beprovided the batteries 100, 100' and 100" so poled as to apply negativecharges to the grids of the respective tubes and thus keep the tubesnormally in a quenched condition.

When tube S1 of Fig. 2 operates and voltage is applied to leads C1 fromleads A1 condenser 18 is charged through resistance 17 by the action ofthe "start rectifier 16 causing current to flow through resistances 19and 20. The voltage drop across resistance 20 is applied between gridand cathode of the S1 through inductance 21 and resistance 28. When thisvoltage reaches the value at which tube S1 ionizes an arc is established in this tube closing the circuit including windings oftransformers t4 and t5. Anode potential is provided, when tube S1 isoperated, through transformer t4, over leads 22 connected to leads C1.Lamp L1 is then lighted through transformer is. When tube S: operatesthe same action takes place for tube S1 as described here for tube S1lighting lamp L2. In addition, however, the voltage on leads C2 is alsoapplied, through leads 23, to the stop" rectifier circuit of tube S1consisting of rectifier 24, resistances 25, 27 and 28 and condenser 26,charging condenser 26 and producing a voltage drop across resistance 28opposing the drop across resistance 20. When the resultant voltagebetween grid and cathode of tube S1 is reduced below the ionizationvalue, tube S1 is quenched at the next negative half cycle of anodepotential and remains all the leads C1, C2, etc tubes S1, S2, Sn arerestored to normal condition, ready to be operated again when the cycleof operations of tubes S1, S2, Sn is repeated. In this way lamps L1, La,LN are lighted once each cycle for an interval determined by the valuesof the resistances and condensers in the rectifier circuits andextinguished a predetermined time thereafter.

In Fig. 5 is shown an arrangement of gas-filled tubes S1", S2", Sn" andcorresponding lamps L1, L2", LN" which, in connection with thearrangement shown in Fig. 2, provides a series of flashing lamps whichare started in sequence, following the operation of tubes S1, S2, Sn,and flash intermittently thereafter until the end of the cycle ofoperations described in connection with Fig. 2 at which time all arequenched and restored to the normal condition to repeat as the cycle ofS1, S2, SN is repeated. The intervals of flashing are determined by theadjustment of the resistance and condenser values in the start and stoprectifier circuits associated with each of the tubes S1", S2", SN". Thedetailed operation of each tube is described in connection with Fig. 1.Lamp L1" will flash intermittently as long as voltage is applied toleads D1. When tube S2 is operated, following the operation of S1, tubeS2" will also begin to ionize and quench in a manner similar to tube S1"and lamp L2" will flash intermittently. In a similar manner, as voltageis applied in sequence to leads D1, D2, DN. the lamps succeeding willbegin to flash intermittently and all will cease flashing when tubes S1,S2, SN are all quenched by SN at the end of the cycle of operations. Bycombination with Fig. 2 of the various circuits described in Figs. 3, 4and 5 any desired sequential arrangement of continuous, single flash orintermittent flashing signals or lamps may be provided. The arrangementof Fig. 1 may also be included to provide intermittent operation not insequence.

While the invention as herein described is shown in certain specificarrangements it is understood that many other arrangements andmodifications may be employed without departing from the scope of theappended claims.

What is claimed is:

l. A gas-filled discharge tube having a gridcathode circuit including abiasing means for applying a negative charge to the grid and a first andsecond resistance connected in series, a starting circuit connectedacross said first resistance, a stopping circuit connected across saidsecond resistance, said starting circuit including a condenser connectedin parallel with said first resistance and a rectifier poled so that theapplication of an alternating current to said starting circuit wil causea charge to build up 'on said condenser of a polarity to apply acrosssaid first resistance a voltage opposing that of said biasing means,said stopping circuit including a condenser connected in parallel withsaid second resistance and a rectifier so poled that the application ofan alternating current to saidstopping circuit will cause a charge tobuild up on the condenser therein of a polarity to apply across saidsecond resistance a voltage aiding that of said biasing means, means forapplying an alternating current to said starting circuit, and meanscontrolled by the discharging of said tube for applying an alternatingcurrent to said stopping circuit.

2. A gas-filled discharge tube having a gridcathode circuit including abiasing means for applying a negative charge to the grid and a first andsecond resistance connected in series, a starting circuit for said tubeconnected across the first resistance, a stopping circuit for said tubeconnected across the second resistance, said starting circuitincludingmeans so that the application of alternating current thereto will buildup a voltage across said first resistance opposing that of said biasingmeans, said stopping circuit including means so that the application ofan alternating current thereto will build up a voltage across saidsecond resistance aiding that 01' said biasing means, means for applyingan alternating current to said starting circuit, and means controlled bythe discharging of said tube for applying an alternating current to saidstopping circuit.

3. A gas-filled discharge tube having a gridcathode circuit including abiasing means for applying a negative charge to the grid and a first andsecond resistance connected in series, a starting circuit for said tubeconnected across the first resistance, a stopping. circuit for said tubeconnected across the second resistance, said starting circuit includingmeans so that the application of alternating current thereto will buildup a voltage across said first resistance opposing that of said biasingmeans, said stopping circuit including means so that the application ofan alternating current thereto will build up a voltage across saidsecond resistance aiding that of said biasing means, means for appyingan alternating current to said starting circuit, additional gas-filleddischarge tubes similar to said first tube, each of said tubes havingstarting and stopping circuits similar to those of said first tube,means controlledby the operation of said first tube for applying analternating current to the starting circuit of the succeeding tube,means controlled by the operation of said last mentioned tube forapplying an alternating current to the starting circuit of the nextsucceeding tube, and means controlled by the operation of the last tubeof the series for applying an alternating current to the stoppingcircuits-of all of said tubes.

4. A series of gas-filled discharge tubes, each of said tubes having agrid-cathode circuit including a biasing means for applying a negativecharge to the grid and a first and second resistance connected inseries, each of said tubes having a starting circuit connected acrossthe flrst resistance and a stopping circuit connected across the secondresistance, each of said starting circuits including means so that theapplication of an alternating current thereto will build up a voltageacross its first resistance opposing that of the biasing means, each ofsaid stopping circuits including means so that the application of analternating current thereto will build up across its second resistance avoltage aiding that of the biasing means, means for applying analternating current to the starting circuit of the first tube of saidseries, means controlled by the operation of each tube in said seriesfor applying an alternating current to 40 the starting circuit of thenext succeeding tube in the series, means controlled by the operation ofthe last tube of the series for applying an alternating current to thestopping circuits of all of said tubes, a second series of gas-filledplying alternating current to the starting circuits of correspondingtubes of said second series, and means controlled by the application ofalternating current to the starting circuits of each or the tubes ofsaid second series for applying alternating current to the stoppingcircuit of the next preceding tube in said second series.

5. A series of gas-filled discharge tubes, each 01 said tubes having agrid-cathode circuit including a biasing means for applying a negativecharge to the grid and a first'and second resistance connected inseries, each of said tubes having a starting circuit connected acrossthe first resistance and a stopping circuit connected across the secondresistance, each of said starting circuits including means so that theapplication of an alternating current thereto will build up a voltageacross its first resistance opposing that of the biasing means, each oi.said stopping circuits including means so that the application of analternating current thereto will build up across its second resistance avoltage aiding that of the biasing means, means for applying analternating current to the starting circuit of the first tube of saidseries, means controlled by the operation of each tube in said seriesfor applying an alternating current to the starting circuit of the nextsucceeding tube in the series, means controlled by the operation of thelast tube of the series for applying an alternating current to thestopping circuits of all of said tubes, a second series of gasfilleddischarge tubes corresponding to those of said first series and eachhaving starting and stopping circuits similar to those of said firstseries of tubes, means controlled by the discharging of each of thetubes of said first series for applying alternating current to thestarting circuits of corresponding tubes of said second series, andmeans controlled by the discharging of each of the tubes of said secondseries for applying alternating current to its stopping circuit.

6. A gas-filled discharge tube having a gridcathode circuit including abiasing means for applying a negative charge to the grid and a first andsecond resistance connected in series, a starting circuit for said tubeconnected across the first resistance, a stopping circuit for said tubeconnected across the second resistance, said starting circuit includingmeans so that the application of alternating current thereto will buildup a voltage across said first resistance opposing that of said biasingmeans, said stopping circuit including means so that the application ofan alternating current thereto will build up a voltage across saidsecond resistance aiding that of said biasing means, means for applyingan alternating 7. A series of gas-filled discharge tubes,'each of saidtubes having a grid-cathode circuit including a biasing means forapplying a negative charge to the grid and a first and second resistanceconnected in series, each of said tubes having a starting circuitconnected across the first resistance and a stopping circuit connectedacross the second resistance, each of said starting circuits includingmeans so that the application of an alternating current thereto willbuild up a voltage across its first resistance opposing that of thebiasing means, each of said stopping circuits including means so thatthe application oi! an alternating current thereto will build up acrossits second resistance a voltage aiding that of said biasing means, meansfor applying an alternating current to the starting circuit 01' thefirst tube of said series, means controlled by the operation of eachtube of said series for applying an alternating current to the startingcircuit of the next succeeding tube of said series, means controlled bythe last tube of said series for applying an alternating current to thestopping circuits of all of said tubes, means for applying analternating current to the cathode-anode circuits of all of said tubes,and signaling means controlled by each of said cathode-anode circuits.

8. A gas-filled discharge tube having a gridcathode circuit including abiasing means for applying a negative charge to the grid and a first andsecond resistance connected in series, a starting circuit for said tubeconnected across the first resistance, a stopping circuit for said tubeconnected across the second resistance, said starting circuit includingmeans so that the application of alternating current thereto will buildup a voltage across said first resistance opposing that of said biasingmeans, said stopping circuit including means so that the application ofan alternating current thereto will build up a voltage across saidsecond resistance aiding that of said biasing means, means for applyingan alternating current tosaid starting circuit, means controlled by thedischarging of said tube for applying an alternating current to saidstopping circuit, and means for controlling the rate at which thevoltage across said first and second resistances is built up.

CHARLES S. DEMAREST.

